31.03.2015 15:43, David Henningsson wrote:
- From the person with the hardware, we will need alsa-info (
https://wiki.ubuntu.com/Audio/AlsaInfo ), and also the max volume where this does not happen. Is -6 dB good enough? -12 dB? I don't know - this is something someone with the hardware must tell us, it cannot simply be guessed.
Another useful piece of information would be what Windows does here.
Please generate a -36 dB 1000 Hz sine wave in Audacity, save as a wav file, play at the maximum volume in Windows, record with a mobile phone (you can use software such as Tape Machine which turns AGC off in the phone). Ideally, the mobile phone should be placed on the table to avoid movements. Play the same wav file in linux (with a known safe attenuation), also record the sound without moving the mobile phone. Compare the recordings in Audacity to find out the attenuation done by Windows.